With the help of Washington Post science writer Schwartz, Osterholm (formerly chief state epidemiologist in Minnesota) sounds a frightening alarm in this compact book. ""I do not believe it is a question of whether a lone terrorist or terrorist group will use infectious disease agents to kill unsuspecting citizens,"" he writes. ""I'm convinced it's really just a question of when and where."" Combining urgent, fact-filled prose with a series of fictional scenarios, the book outlines the scope of the potential threat. Osterholm introduces the various types of people and organizations he thinks might be planning to unleash an epidemic on a major U.S. city; he covers the six diseases that pose the greatest threat (such as anthrax and smallpox); he explains how underprepared we are for such an attack; and he proposes a ""seven-point plan for change"" (including stockpiling antibiotics and vaccines). Its hard to know whether Osterholm's panic is justified, as he prudently declines to get into the sort of detail that could facilitate a terrorist attack. But although the threats he describes are bone-chilling, his pro-public health, seven-point plan is sensible and compelling. (Sept.)